Salicylglycolic acid and process of making same.



UNITED STATES ATENT QFFICE.

HERMANN VIETH, OF LUDWIGSHAFEN, GERMANY, ASSIGNOR TO KNOLL 8t COMPANY, OF SAME PLACE.

SALICYLGLYCOLIC ACID AND PROCESS OF MAKING SAME.

SPIEGIFIGATION forming part of Letters Patent No. 672,156, dated April 16, 1901:

Application filed December 8, 1900. Serial No. 39,117. ($peoimens.)

T at whom it may concern Be it known that I, HERMANN VIETH, a subject of the Duke of Anhalt, and a resident of Ludwigshafen-on-the-Rhine, Kingdom of Bavaria, German Empire, have invented a new and useful Improvement in Salicylglycolic' Acid and Processes of Making the Same, of which the following is a specification.

The salicylglycolate of ethyl was obtained by Send in the way of heatinga mixture of salicylate of sodium and monochloracetic ether to about 180 centigrade. Senff, however, failed in his further trials of converting this ether into the free salicylglycolic acid by sa- I 5 ponification. (See I/iebz'gs Annalen der C'hem ie 208, page 27-6.) In studying this question I found that this way is still practicable provided the process of saponification is carried on at a moderate temperature. The higher the temperature the less salicylglycolic acid is formed, and at the boiling-point nearly the Whole mass of the ether is decomposed into salicylic and glycolic acid.

Instead of the ethyl ether other ethers may be saponified.

Example 1: Ten parts of sallicylglycolate of ethyl are dissolved in a mixture of sixteen parts of a twenty-five-per-cent. solution of caustic soda, (two molecules,) with the same 0 weight of ice. The clear liquid containing now basic calicylglycolate of sodium is kept at a temperature of about 15 centigrade for about twenty minutes and then poured slowly into twenty parts of muriatio acid of twenty 3 5 per cent, keeping the mixture cool and stirring thoroughly. The precipitate thus obtained is separated from the liquor, well washed with water, and dried. It forms a white crystalline mass of nearly pure salicyl- 4o glycolic acid. The yield is almost equal to the theory.

Example 2: Ten parts of salicylglycolate of ethyl are dissolved in fifty parts of eighty-percent. sulfuric acid. This liquid is kept at a 5 temperature of about centigrade for about one hour. During this time the solution is converted into a mass of crystals. Ice and water being added, the crystals are separated and washed with water. Example 3: Ten parts of salicylglycolate of ethyl are dissolved in sixteen parts of atwentyfive-per-cent. solution of caustic soda, exactly as in the first example. Then the solution is neutralized with an acid, (either mu riatic acid or salicylglycolic acid.) Hereby the neutral salicylglycolate of sodium is formed. This salt may be obtained in a crystalline form either by adding com mon salt-or alcohol to the liquor or by evaporating the solution in a vacuum pan.

The salicylglycolic acid crystallizes, for instance, out of chloroform or benzol in wellformed crystals, showing,contrary to salicylic acid, a nearly parallel extinction of the polarized lightmelting-point about 132 centigrade. Its solution is turned reddish violet by perchlorid of iron. The acid dissolves without decomposition in a solution of soda, butis decomposed by hot caustic alkalies or acids.

It undergoes the same decomposition by the intestine liquid, but resists the gastric juice. Moreover, the salicylglycolic acid is characterized by forming acid alkali salts of a wellcrystallized form. For instance, on pouring a small quantityof common-salt liquor to the mixture of the watery solutions of salicylglycolic acid (one molecule) and its neutral sodium salt (one molecule) the whole mixture changes into a mass of crystals, which being pressed off may be recrystallized from alco- 8o hol. Pure water, however, would decompose the saltmelting point 203 centigradethe neutral salt melting at 260 centigrade.

The salts of the earth alkalies are little soluble in cold water and crystallize. The salts of the metalsfor instance, iron, silver, bismuth, and mercuryare nearly insoluble in water. The salicylglycolates have not the sweetish saline taste of the sodium salicylate, but taste rather bitter.

The acid and itssalts are valuable remedies in polyarthritis and all diseases usually treated with salicylates. The dose is 0.5 gram per day.

What I claim as my invention is 1. The process of manufacturing the salicylglycolic acid and its salts by saponifying its ethers ata temperature below cent-igrade substantially as described.

2. Asa new product the salicylglycolic acid 100 herein described the crystals of which have a melting-point of about 132 centigrade, showing a nearly parallel extinction of the polar- In testimony that I claim the foregoing as my invention I have signed my name, in pres- IO ence of two witnesses, this 23d day of Novemizedlightandin stateof solution being turned 1 her, A. D. 1900.

' into reddish violet by perchlorid-of iron, dissolving without decomposition in a solution of soda and decomposing by hot caustic alkalies or acids.

HE RMANN VIEIH.

Witnesses:

JACOB ADRIAN, OsWALD KRUG. 

